Blower Motor Resistor

BigDaddyGun · June 1, 2010

Hi, I've replaced the blower motor resistor once and smoke came out from under the dash and it quit, i wasn't sure if it was the resistor or something else that smoked, so i got a new blower motor resistor and I have replaced it again and it worked within a mile or so then i could smell it burning again with the fan selector on #5 and shut the fan off. The fan will work an speeds 1-4 but when turned on #5 that is when i smell the burning. I'm doubting that if replacing the 7 pin wiring harness will fix this problem since it has worked fine the last 4 days on speeds 1-4, and I don't want to start throwing parts at it,,, what should I do next??????????

bossier62guy · June 1, 2010

Hi, I've replaced the blower motor resistor once and smoke came out from under the dash and it quit, i wasn't sure if it was the resistor or something else that smoked, so i got a new blower motor resistor and I have replaced it again and it worked within a mile or so then i could smell it burning again with the fan selector on #5 and shut the fan off. The fan will work an speeds 1-4 but when turned on #5 that is when i smell the burning. I'm doubting that if replacing the 7 pin wiring harness will fix this problem since it has worked fine the last 4 days on speeds 1-4, and I don't want to start throwing parts at it,,, what should I do next??????????

Have you checked the wiring and plug for signs of overheating or melting? Was the old resistor actually bad (burned, etc.)?

MS3DALE · June 1, 2010

Hi, I've replaced the blower motor resistor once and smoke came out from under the dash and it quit, i wasn't sure if it was the resistor or something else that smoked, so i got a new blower motor resistor and I have replaced it again and it worked within a mile or so then i could smell it burning again with the fan selector on #5 and shut the fan off. The fan will work an speeds 1-4 but when turned on #5 that is when i smell the burning. I'm doubting that if replacing the 7 pin wiring harness will fix this problem since it has worked fine the last 4 days on speeds 1-4, and I don't want to start throwing parts at it,,, what should I do next??????????

Have you checked the wiring and plug for signs of overheating or melting? Was the old resistor actually bad (burned, etc.)?

+1 Theres a TSB out for this issue,Your supposed to change both the resistor and the harness/connector.

pm26 · June 1, 2010

Does this TSB also affect 2006 trucks? Has GM corrected this problem?

txab · June 1, 2010

Does this TSB also affect 2006 trucks? Has GM corrected this problem?

It's always best to replace the harness whenever the resistor is changed after it has toasted itself

pm26 · June 1, 2010

Does this TSB also affect 2006 trucks? Has GM corrected this problem?

It's always best to replace the harness whenever the resistor is changed after it has toasted itself

Your statement does not answer either of my questions.

BigDaddyGun · June 1, 2010

When i replaced the original resistor, everything worked fine (which made me believe it was just the resistor) until I left it on Fan Speed 5 and the smoke rolled. I have now put the 2nd one in and had no problems until i had it on speed 5 and i could literally smell it getting hot so i have not used speed 5 and it has been fine, (but i DO want to go ahead and fix it right). None of the harness or where it plugged into seemed burnt at all, even on the 2nd one that burned up on speed 5. I'm definitely (no electrician at all), but (wires) don't generally go bad, and if it works on speeds 1-4 with no problem,, only getting hot and or burning up on speed 5 when the blower is on full power (from what i've researched) and no burn spots or melting of the plastic on either end it seems that if i replace the harness it won't help. I "DO" hope it is that easy, and have already ordered a harness which s/b here tomorrow, but i just don't want to replace the harness and have the resistor and harness burn up and have to replace them both again.

I did so posts on this elsewhere on the site but did not find anything that matched my specific question.

txab · June 1, 2010

Does this TSB also affect 2006 trucks? Has GM corrected this problem?

It's always best to replace the harness whenever the resistor is changed after it has toasted itself

Your statement does not answer either of my questions.

Yes 2006 trucks are affected by a TSB on this issue. From what I remember it goes through at least 2007. No matter, if you fry the resistor the connector can become damaged.

bossier62guy · June 2, 2010

When i replaced the original resistor, everything worked fine (which made me believe it was just the resistor) until I left it on Fan Speed 5 and the smoke rolled. I have now put the 2nd one in and had no problems until i had it on speed 5 and i could literally smell it getting hot so i have not used speed 5 and it has been fine, (but i DO want to go ahead and fix it right). None of the harness or where it plugged into seemed burnt at all, even on the 2nd one that burned up on speed 5. I'm definitely (no electrician at all), but (wires) don't generally go bad, and if it works on speeds 1-4 with no problem,, only getting hot and or burning up on speed 5 when the blower is on full power (from what i've researched) and no burn spots or melting of the plastic on either end it seems that if i replace the harness it won't help. I "DO" hope it is that easy, and have already ordered a harness which s/b here tomorrow, but i just don't want to replace the harness and have the resistor and harness burn up and have to replace them both again.

I did so posts on this elsewhere on the site but did not find anything that matched my specific question.

I'm thinking that the red wire (direct power from underhood fuse panel) is overheating. Speeds 1-4 actually use the resistor assembly to step up/down the power to control fan speed. Speed 5 energizes a relay, which is part of the resistor assembly, that sends 12vdc to the blower motor to give you high speed operation. Let us know how it turns out.

BigDaddyGun · June 2, 2010

When i replaced the original resistor, everything worked fine (which made me believe it was just the resistor) until I left it on Fan Speed 5 and the smoke rolled. I have now put the 2nd one in and had no problems until i had it on speed 5 and i could literally smell it getting hot so i have not used speed 5 and it has been fine, (but i DO want to go ahead and fix it right). None of the harness or where it plugged into seemed burnt at all, even on the 2nd one that burned up on speed 5. I'm definitely (no electrician at all), but (wires) don't generally go bad, and if it works on speeds 1-4 with no problem,, only getting hot and or burning up on speed 5 when the blower is on full power (from what i've researched) and no burn spots or melting of the plastic on either end it seems that if i replace the harness it won't help. I "DO" hope it is that easy, and have already ordered a harness which s/b here tomorrow, but i just don't want to replace the harness and have the resistor and harness burn up and have to replace them both again.

I did so posts on this elsewhere on the site but did not find anything that matched my specific question.

I'm thinking that the red wire (direct power from underhood fuse panel) is overheating. Speeds 1-4 actually use the resistor assembly to step up/down the power to control fan speed. Speed 5 energizes a relay, which is part of the resistor assembly, that sends 12vdc to the blower motor to give you high speed operation. Let us know how it turns out.

-______________________________________________________________________

Just Got my part, will either replace it tonight or tomorrow, but will give feedback when I'm done.